Johnson J10RLSUR, Service Manual

Page: 91 / 229

89
IGNITION
IGNITION SYSTEM TESTS
5
IGNITION SYSTEM
TESTS
The following series of steps will systematically
isolate a problem area in the ignition system. To
reduce troubleshooting time and to avoid incom-
plete results, perform these steps in the order writ-
ten.
Total Ignition Output Test
Twist and remove the leads from both spark
plugs.
Adjust the gap on the spark tester to 1/2 in. (12
mm). Connect tester leads to the spark plug
leads. Secure tester clip to a clean engine ground.
IMPORTANT:
To prevent high voltage arc,
route tester leads at least 2 in. (51 mm) from any
metal surface.
If equipped, install the clip onto the emergency
stop switch. Crank the engine. Spark should jump
each tester gap alternately.
•
If tester shows good output on both cylinders,
go to
Power Pack Running Output on p. 94.
•
If tester shows good output on one cylinder, go
to
Power Pack Cranking Output on p. 94.
•
If tester shows no output, go to Stop Circuit
Tests .
IMPORTANT:
It is possible for the ignition sys-
tem to have a problem but still produce good out-
put. If the engine pops or backfires during starting,
the ignition may be out of time. Check the follow-
ing:
•
Coil primary wire routing
•
Spark plug lead routing
•
Flywheel condition and location
•
Synchronization and linkage adjustments
Stop Circuit Tests
Elimination Test
Disconnect 5-pin Amphenol connector between
ignition plate and power pack.
Insert jumper wires between the "A," "B," "C," and
"D" terminals of the 5-pin connector.
CAUTION
All cranking output tests must be per-
formed with spark plugs installed and
torqued in the cylinder head. If necessary
to remove the spark plugs, be sure to keep
the spark tester away from open spark
plug holes.
CAUTION
To avoid possible shock hazard, do not
handle ignition coils or spark tester during
cranking tests.
COA4308
CAUTION
To avoid possible shock hazard, do not
handle ignition coils or spark tester during
cranking tests.
DR4185